Apple-2-Tools/bradgrantham-apple2e
1
0
Fork 0
mirror of https://github.com/bradgrantham/apple2e.git synced 2024-06-26 02:29:36 +00:00
Code Issues Projects Releases Wiki Activity

another LSR and another EOR

Browse Source
This commit is contained in:
Brad Grantham 2016-11-06 14:18:17 -08:00
parent dcc884487e
commit 21a5e8f112
1 changed files with 21 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
apple2e.cpp
View File

@ -629,6 +629,18 @@ struct CPU6502
break;
}
case 0x4E: {
int addr = read_pc_inc(bus) + read_pc_inc(bus) * 256;
if(debug & DEBUG_DECODE) printf("LSR %04X\n", addr);
unsigned char m = bus.read(addr);
flag_change(C, m & 0x01);
m = m >> 1;
flag_change(N, m & 0x80);
flag_change(Z, m == 0);
bus.write(addr, m);
break;
}
case 0x4A: {
if(debug & DEBUG_DECODE) printf("LSR A\n");
flag_change(C, a & 0x01);
@ -862,6 +874,15 @@ struct CPU6502
break;
}
case 0x45: {
unsigned char zpg = read_pc_inc(bus);
if(debug & DEBUG_DECODE) printf("EOR %02X\n", zpg);
a = a ^ bus.read(zpg);
flag_change(N, a & 0x80);
flag_change(Z, a == 0);
break;
}
case 0x49: {
unsigned char imm = read_pc_inc(bus);
if(debug & DEBUG_DECODE) printf("EOR #%02X\n", imm);